[118577] in North American Network Operators' Group
Re: ISP port blocking practice
daemon@ATHENA.MIT.EDU (Dan White)
Fri Oct 23 22:36:30 2009
Date: Fri, 23 Oct 2009 21:35:31 -0500
From: Dan White <dwhite@olp.net>
To: Justin Shore <justin@justinshore.com>
In-Reply-To: <4AE23194.3010501@justinshore.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 23/10/09 17:43 -0500, Justin Shore wrote:
>> It does block incoming SMTP traffic on that well known port.
>
> Then the customer should have bought a class of service that permits
> servers.
That justification is a slippery slope. At what point do you draw the line
on what constitutes business use? Is running a web server business use? A
mail server? What about a server which participates in a peer to peer
network? VPN?
I certainly think you're within your right as a network operator to
determine what is business use. I don't happen to feel that running a
protocol server in and of itself meets that definition.
>> Would you consider restricting a customer's outgoing port 25 traffic to a
>> specific mail server a step over the net neutrality line?
>
> I do this all the time. For example I don't let my customers send or
> receive mail (or any traffic for that matter) from prefixes originating
> from AS32311 (Colorado spammer Scott Richter). Now if I was blocking
> mail to dnc.org, gop.com, greenpeace.org, etc or restricting Vonage to
> .05% of my bandwidth then yeah that would violate net neutrality
> principles. The difference is one stifles speech and is
> anti-competitive. The other mitigates a network security and stability
> risk.
I think I worded my question a bit wrong. I meant to hypothetically propose
a common scenario: You only allow your customers to connect to your SMTP
server, and if they attempt to connect to *any* other SMTP server, they are
blocked or redirected to your SMTP server.
--
Dan White
